Though concern regarding the Zika virus has already spurred some of the world's top athletes to skip out on the Olympics in Brazil, the risk of the games causing widespread Zika exportation is low as long as precautions are taken, according to a CDC model released Wednesday.

Here are three things to know about the risk of international Zika exportation as a result of travel to Rio de Janeiro, according to CDC analysis:

1. Low probability: Approximately 350,000 to 500,000 tourists and athletes from 207 countries will land in Brazil for the 2016 Olympic and Paralympic Games, but that number accounts for less than a quarter of international travel to Zika-affected regions in 2015. The probability of contracting Zika while visiting Brazil for the games is low because the Olympics will not begin until Rio's winter season — the dryer weather will likely reduce the mosquito population.

2. At-risk nations: The CDC estimated four nations as being particularly vulnerable to imported Zika. Citizens of these countries are currently not traveling to Zika-affected regions, thereby heightening the measure of impact on the possible importation of the virus. The four nations — Chad, Djibouti, Eritrea and Yemen — also have environmental conditions and population susceptibility to facilitate local Zika transmission once the virus comes to shore.

3. Prevention: The CDC recommends pregnant women not travel to the games, all visitors protect themselves from mosquitoes both during their attendance and for three weeks after returning home and all travelers take precautions against sexual transmission of the virus.